Today's computer systems include many electrical components that produce significant amounts of heat. It is necessary to remove the heat from the electrical components, and from the computer enclosures, to prevent the components from overheating and becoming damaged or destroyed.
Most computer systems, including laptop computers, desktop computers and computer servers, include at least one cooling fan which generates a flow of cooling air that is directed over the electrical components that produce heat. Typically, ambient air is drawn into a computer housing through an inlet located on a first side of the computer housing, the air passes over the electrical components, and the air flow then exits through an outlet on a second opposite side of the computer housing.
While a flow of cooling air produced by one or more cooling fans is sufficient for many applications, in some high power and densely packaged computer systems, cooling fans alone are unable to remove a sufficient amount of heat from the enclosure to prevent damage to the electrical components, even when the air is at normal ambient temperatures. When the air used for cooling is at elevated temperatures, this problem becomes even worse.
To increase the amount of heat which can be removed from an enclosure by a flow of cooling air, some electrical components are attached to or mounted on heat sinks. The heat sinks typically have cooling fins that increase the amount of surface area which can be used for heat transfer to the flow of cooling air. While this helps to remove heat from the electrical components, even the use of heat sinks is insufficient in certain applications to prevent overheating.
For instance, in some situations a plurality of computer servers are mounted in a rack, and multiple racks of computer servers are located in the same room. In this type of environment, the amount of heat produced by all of the electrical components of all of the computer servers is dumped into the room, and this raises the ambient temperature within the room. The temperature differential between the temperature of the ambient air and the temperature of the electrical components is one of the key factors in the ability of a flow of cooling air to remove heat from the electrical components. When the ambient temperature rises, it can become impossible to remove a sufficient amount of heat from the electrical components to prevent damage.
For all the above reasons, in certain applications it is necessary to employ auxiliary cooling systems to help remove enough heat from the electrical components of a computer. The auxiliary cooling systems are usually employed to cool the air that is blown over the electrical components. And because the air used to cool electrical components of a computer system is drawn from the area immediately surrounding the computer enclosure, this usually means cooling the air in the room in which the computer system is located.
An auxiliary cooling system could simply be an air conditioning system that helps to cool the air in a room where multiple computers are located. In the case of a room with multiple racks of rack mounted servers, there may be specialized systems that generate cool air that is provided directly to the servers.
Unfortunately, providing the auxiliary cooling systems involves a significant extra expense. Also, it is necessary to provide electrical power to run such systems, and maintenance of the systems may also be required. Some such auxiliary cooling systems use water as a heat sink, which also requires significant water routing and handling systems. Moreover, in certain applications, such as aboard ships or submarines, the extra space required for the auxiliary cooling systems is problematic.